1. Field of the Invention:
The present invention relates to an electrical circuit for supplying high voltage AC electrical energy to a complex load, and more particularly, to such an electrical circuit for operating a high voltage corotron device, including means for regulating resistive current through the corotron.
2. Description of the Prior Art:
Prior art circuits for operating and regulating resistive current through a complex load, such as a corotron, leave much to be desired. One such circuit provides, as a portion of a high voltage output transformer coupled with an inverter, an extended winding to power a "compensating" capacitor connected to a corotron. The winding and capacitor are chosen so that current flowing in this capacitor is equal to, but opposite in polarity to, the capacitive current flowing in the shunt capacitive component of the load corotron. If this capacitor and the winding are properly chosen and adjusted, the only current flowing through a sensing resistor coupled serially with the load is the resistive component of that load. Such an arrangement leaves much to be desired in a circuit which should be precisely controlled, and is particularly very limited in its ability to compensate for variations in variable, stray, load capacitances. In addition, the choice of capacitance value and extra winding turns is a difficult one, indeed.
It is, therefore, an object of the present invention to provide an improved circuit for precisely regulating resistive current through a complex load.